MANILA, Philippines – President Rodrigo Duterte has vowed to expel American troops from the Philippines, accused the CIA of plotting to kill him and insulted President Barack Obama with an obscenity.

But beyond the blasts of hyperbole – he recently compared himself to Hitler – lies a real and potentially historic shift in Philippines foreign policy.

In public statements and interviews during the past week, Duterte’s top foreign policy advisers said he was seeking to break the Philippines out of the United States’ orbit and signal to China that he is ready to negotiate closer ties after years of wrangling over its military presence in the South China Sea.

The move is a radical departure for a country that has historically been the most dependable U.S. ally in Southeast Asia, and could undermine Obama’s so-called pivot to Asia, a keystone of his foreign policy. That strategy depends on U.S. allies to counter China’s increasing power in the region.

On the South China Sea, Duterte’s move has already tilted the balance of power, said Richard Javad Heydarian, a political scientist at De La Salle University in Manila. By declining to press claims against China over disputed territory there, despite a favorable ruling by a United Nations tribunal, Duterte has made it hard for the U.S. to galvanize international pressure on China over the issue.

“Almost single-handedly Duterte has reshaped the regional strategic dynamics, with both Beijing and Washington recalibrating their next move in the South China Sea as they try to anticipate the Filipino strongman’s foreign policy trajectory,” Heydarian said.

Duterte, who is expected to visit Beijing this month, has made no secret of his worldview.

“I will be reconfiguring my foreign policy,” he said in a speech last week. And at some point, “I will break up with America.”

Often after Duterte makes an over-the-top pronouncement, an aide emerges to walk it back. But in this case, the retreat was slight.

Duterte was not seeking a breakup with the U.S., the president’s spokesman, Ernesto Abella, explained, so much as “an open relationship.”

On Tuesday, Foreign Secretary Perfecto Yasay Jr. went further, explaining in a statement posted online that the Philippines needed to chart a new, independent foreign policy because “America has failed us.”

Since the Philippines won independence from the U.S., its former colonial master, in 1946, Yasay wrote, “the United States held on to invisible chains that reined us in towards dependency and submission as little brown brothers not capable of true independence and freedom.”

U.S. officials have sought to deflect and diminish the significance of these statements, and emphasize the benefits to the Philippines of the U.S. presence.

“Our history of cooperation spans 70 years, and our commitment to this country remains unchanged,” the U.S. ambassador, Philip S. Goldberg, said Wednesday in a speech to the American Chamber of Commerce of the Philippines here. “The Philippines is a key strategic partner of the United States, and our military alliance, development assistance and commercial cooperation continue.”

Although Duterte declared last month that the annual joint military exercises now underway on the island of Luzon would be the last during his administration, U.S. officials said his government had made no formal requests to halt any programs. Nor has it followed up on Duterte’s threat to eject U.S. forces from the southern Philippines, where a rotating force of 50 to 100 troops helps combat Abu Sayyaf, an Islamic-themed kidnap-for-ransom gang.

“As it has been for decades, our alliance with the Philippines is ironclad,” the U.S. defense secretary, Ash Carter, said late last month.

The U.S. is giving the Philippines more than $90 million in military aid this year and has provided more than $1 billion in nonmilitary support over the past five years, much of it for disaster relief, U.S. officials said.

On Friday, Defense Secretary Delfin Lorenzana said that “we can live without” the military aid.

Some of the tension between the allies has come from international outrage over Duterte’s bloody campaign against drugs, which has led to the killing of about 1,400 suspects by the police and hundreds of other extrajudicial killings. It was his concern that Western powers would lecture him over the policy that prompted Duterte’s denunciation of Obama, as well as similar tirades against the U.N. and the European Union.

Duterte, 71, identifies himself as a socialist and views the West through the lens of the Cold War and the Philippines as the victim of historic U.S. imperialism.

But the recalibration also provides an opportunity to improve ties with China, the region’s biggest military power and largest economy. China was the Philippines’ second-largest trading partner last year, with total trade of $17.6 billion. (The U.S. was third and Japan first.)

China has been making inroads in the region with promises of investment and with its military expansion in the South China Sea, where it has occupied islands claimed by the Philippines, Vietnam and other countries, in some cases building forts.

At the same time, despite the sometimes harsh words, Philippine officials have made it clear that the new president does not want to abandon the U.S.

“While we would like to foster a closer relationship with China, we will certainly not engage in any alliance with China in a military viewpoint because that has never been the intention of the president,” Yasay, the foreign secretary, said at a Senate hearing on Thursday. “The president, on many occasions, has said categorically that he will only have one military alliance, and our only ally in that respect is the United States.”

That statement may suggest a future in which the Philippines plays the big powers against each other.